1. Field
The present invention relates to an organic light emitting display.
2. Related Art
In recent years, a flat panel display (FPD) increasingly becomes important with the development of multimedia. Hence, various flat panel displays such as a plasma display panel (PDP), a field emission display (FED), and an organic light emitting display (OLED) have been put to practical use.
In portionicular, an organic light emitting display has an advantage in that it has a high response speed lower than 1 ms and low consumption power, as well as emits light by itself. In addition, the organic light emitting display is advantageous as a motion image display medium because it does not have a trouble in the view angle without respect to its size. Furthermore, the organic light emitting display has come into the spotlight as a next generation flat panel display because it can be simply manufactured with existing semiconductor manufacturing processes at a low temperature.
FIG. 1 is a plan view illustrating a structure of an organic light emitting display according to the prior art, FIG. 2 is a portionially enlarged view of the organic light emitting display in FIG. 1, and FIG. 3 is a cross sectional view of the organic light emitting display taken along line I-I′ of FIG. 2.
Referring to FIGS. 1 to 3, an organic light emitting display according to the prior art comprises a substrate 100 comprising a non-emission region N and an emission region E, on which there are arranged sub-pixels, each comprising a first electrode 110, an emission layer 120, and a second electrode 130. Here, a first region where sub-pixels are arranged is defined as an emission region E, and a second region other than the first region is defined as a non-emission region N.
On the non-emission region N of the substrate 100 there are provided sealant 160 and wires (not shown) to apply electrical signals to the first electrode 110 and the second electrode 130.
More specifically, the first electrode 110 is patterned on the substrate 100 in a stripe form. And, wires (not shown), which are spaced from the first electrode 110 and have the same material as the first electrode 110, are provided. On a portion of the first electrode 110 and wires (not shown) there is provided an insulating film 115 comprising an opening 116 for exposing a portion of the first electrode 110 and a contact portion 117 for exposing a portion of the wires (not shown). On the insulating film 115 there are provided barrier ribs 118 formed to be spaced from each other in the direction of intersecting the first electrode 110, and in the opening 116 there is provided the emission layer 120. The second electrode 130 is located on the substrate comprising the emission layer 120 and contact portion 117, and the second electrode 130 is patterned by the barrier ribs 118. And, the sealant 160 is provided on the non-emission region N of the substrate 100 to surround the emission region E. And, the substrate 100 provided with the sub-pixels is attached to an encapsulation substrate (not-shown) by the sealant 160 to protect the emission portion from external moisture or oxygen.
At this time, however, the sealant 160 can be flowed into the emission region E as shown in FIGS. 2 and 3(C). That is, a capillary phenomenon created by a pressure applied when the substrate 110 and the encapsulation substrate 170 are attached to each other causes the sealant 160 to flow into the emission region E along the lower space of barrier ribs having overhang structures.
The flowed sealant 160 may cause damage to an outer circumference of the emission layer 120, thereby to reduce reliability and emission efficiency of elements.